perf: format big files first

src/alejandra_cli/src/find.rs

@@ -1,4 +1,5 @@
 use std::collections::HashSet;
+use std::process::exit;
 
 pub(crate) fn nix_files(include: &[&str], exclude: &[String]) -> Vec<String> {
     let include: HashSet<_> =
@@ -6,19 +7,26 @@ pub(crate) fn nix_files(include: &[&str], exclude: &[String]) -> Vec<String> {
     let exclude: HashSet<_> =
         exclude.iter().flat_map(|s| nix_files_in_path(s)).collect();
 
-    let mut paths: Vec<_> = include.difference(&exclude).cloned().collect();
+    let mut paths: Vec<_> = include
+        .difference(&exclude)
+        .cloned()
+        .map(|path| (len_of(&path), path))
+        .collect();
 
-    paths.sort_unstable();
-    paths
+    paths.sort_unstable_by(|(len_a, _), (len_b, _)| len_b.cmp(len_a));
+
+    paths.into_iter().map(|(_, path)| path).collect()
 }
 
 fn nix_files_in_path(path: &str) -> HashSet<String> {
     walkdir::WalkDir::new(path)
         .into_iter()
         .filter_entry(is_nix_file_or_dir)
-        .filter_map(|entry| match entry {
-            Ok(entry) => Some(entry),
-            Err(_) => None,
+        .filter_map(|entry| {
+            match entry {
+                Ok(entry) => Some(entry),
+                Err(_) => None,
+            }
         })
         .filter(is_nix_file)
         .map(to_full_path)
@@ -37,3 +45,14 @@ fn is_nix_file_or_dir(entry: &walkdir::DirEntry) -> bool {
 fn to_full_path(entry: walkdir::DirEntry) -> String {
     entry.path().to_str().unwrap().to_string()
 }
+
+fn len_of(path: &str) -> u64 {
+    match std::fs::metadata(&path) {
+        Ok(meta) => meta.len(),
+        Err(err) => {
+            eprintln!("Could not get the size of file at: {path}");
+            eprintln!("Got error: {err}");
+            exit(1);
+        },
+    }
+}